UPDATE 1-S.Korea says U.S., N.Korea will restart dialogue 'soon'

SEOUL, Aug 22 (Reuters) - The United States and North Korea are expected to reopen denuclearization talks soon and it would "go well," a senior South Korean official said on Thursday, boosting hopes for progress in negotiations after a prolonged stalemate.

South Korea's deputy national security adviser Kim Hyun-chong gave his upbeat assessment after meeting with U.S. envoy for North Korea Stephen Biegun in Seoul.

"My impression was that North Korea and the United States would carry out dialogue soon, and it would go well," Kim told reporters after the one-hour meeting, without elaborating.

Working-level talks between the United States and North Korea have yet to restart since they were stalled by the failed second summit between U.S. President Donald Trump and North Korean leader Kim Jong Un in Hanoi in February.

Trump and Kim met again in June at the inter-Korean border and agreed to reopen negotiations.

The South Korean official also said that South Korea's presidential National Security Council will convene later on Thursday to review an intelligence-sharing pact with Japan, that Seoul had threatened to scrap amid a spiralling diplomatic and trade spat.

The General Security of Military Information Agreement (GSOMIA) could expire on Saturday if either side decides not to roll it over.

According to Kim, the South Korean official, Biegun raised the issue, which has worried Washington as the accord is instrumental in three-way efforts to counter North Korea's nuclear and missile threats.

"I've told him we'll carefully examine it and make a decision in a way that serves our national interest," the South Korean deputy national security adviser said.